The third round was suspended due to darkness with seven players left on the course. The tournament was delayed for nearly six hours by bad weather on Friday and is still trying to catch up.
The second round was completed Saturday morning. The third round did not begin until 1:40 p.m. local time. The round will resume at 9:30 a.m. ET Sunday with the final round to start an hour later.
Mathew Goggin stands alone in second place at minus-10, but he has three holes still to play. Brian Henninger has third place to himself at 9-under-par 207 after a round of 68 at Willow Creek Country Club.
Greg Chalmers, Kris Cox and Tim Wilkinson are tied for fourth place at minus-8. They were joined there by second-round leader Brendon De Jonge, who is even par through 15 holes of his third round.
Willis got off to a hot start with birdies on three of his first four holes to jump to minus-9. He picked up another birdie on the par-3 seventh.
The 31-year-old stumbled to his only bogey on the eighth. Willis parred his next four holes around the turn. He got back to minus-10 with a birdie on the par-4 13th.
Willis closed with a 12-foot birdie putt at the last to take the lead outright.
'I think the last birdie was 12 feet, but in all honesty I couldn't see it,' admitted Willis. 'I was beginning to think our group had made a bad decision to finish our round. However, having that last putt go in was nice. It will be nice to sleep in tomorrow.'
Goggin played the front side at even par with one birdie and one bogey. Around the turn, he birdied 10 and 11 to move to 9 under. After a par on the 12th, Goggin birdied 13 to get within one of the lead. He parred his next two holes before played was called for the day as he played the 16th.
Dave Christensen completed a third-round, 4-under 68 to move into eighth place at 7-under-par 209. Robert Garrigus and Greg Kraft are one stroke further back at minus-6, but both have to complete two holes.